tree 2a9925ced7fab0e810a719884f1ca12d4a3edd70
parent a524b9b06be2e0c24d8abc6528cf29316cfe8dc5
author DRC <information@libjpeg-turbo.org> 1604710315 -0600
committer DRC <information@libjpeg-turbo.org> 1604869021 -0600

Build: Fix test failures w/ Arm Neon SIMD exts

Regression caused by
a46c111d9f3642f0ef3819e7298846ccc61869e0

Because of 7723d7f7d0aa40349d5bdd1fbe4f8631fd5a2b57, which was
introduced in libjpeg-turbo 1.5.1 in response to #81, merged upsampling/
color conversion is disabled on platforms that have SIMD-accelerated
YCbCr -> RGB color conversion but not SIMD-accelerated merged
upsampling/color conversion.  This was intended to improve performance
with the Neon SIMD extensions, since those are the only SIMD extensions
for which those circumstances apply.  Under normal circumstances, the
separate "plain" (non-fancy) upsampling and color conversion routines
will produce bitwise-identical output to the merged upsampling/color
conversion routines, but that is not the case when skipping scanlines
starting at an odd-numbered scanline.  The modified test introduced in
a46c111d9f3642f0ef3819e7298846ccc61869e0 does precisely that in order to
validate the fixes introduced in
9120a247436e84c0b4eea828cb11e8f665fcde30 and
a46c111d9f3642f0ef3819e7298846ccc61869e0.

Because of 7723d7f7d0aa40349d5bdd1fbe4f8631fd5a2b57, the segfault fixed
in 9120a247436e84c0b4eea828cb11e8f665fcde30 and
a46c111d9f3642f0ef3819e7298846ccc61869e0 didn't affect the Neon SIMD
extensions, so this commit effectively reverts the test modifications in
a46c111d9f3642f0ef3819e7298846ccc61869e0 when using those SIMD
extensions.  We can get rid of this hack, as well as
7723d7f7d0aa40349d5bdd1fbe4f8631fd5a2b57, once a Neon implementation of
merged upsampling/color conversion is available.